1.1.5.10 FAD bound cofactor 727253 1.1.5.10 FAD the enzyme contains a flavin adenine dinucleotide (FAD)-containing dehydrogenase domain. Compared to the intact enzyme, the FAD-containing dehydrogenase domain shows increased catalytic efficiency with cytochrome c as the electron acceptor, but it completely loses the ability to use coenzyme Q10. The FAD containing dehydrogenase domain is no longer associated with the cell membrane, and it can not support the utilization of D-lactate as a carbon source 763205 1.1.5.10 FAD the purified enzyme has a spectrum typical of a flavoprotein. The change induced in the spectrum on addition of D-malate or D-lactate suggests the formation of a flavin semiquinone. Flavin can be removed by treatment with acid ammonium sulfate, and activity can be restored to the inactive apoenzyme by addition of FAD, but not of FMN or riboflavin 724205 1.1.5.10 Fe-S center the enzyme contains an Fe-S oxidoreductase domain. The Fe-S oxidoreductase domain functions as an electron transfer component to facilitate the utilization of quinone as an electron acceptor by the enzyme (Fe-S D-iLDH), and it helps the enzyme associate with the cell membrane 763205 1.1.5.10 quinone - 727253